Gregory Palamas

Gregory Palamas (c. 1296–1359) was a Byzantine theologian, hesychast monk, and Archbishop of Thessalonica who became the foremost defender of the contemplative prayer tradition practiced on Mount Athos. He formulated the theological distinction between God's unknowable essence and His communicable divine energies, arguing that hesychast monks genuinely participate in the uncreated light of God — the same light witnessed on Mount Tabor — without thereby comprehending the divine nature itself. This teaching, challenged by the Calabrian monk and philosopher Barlaam of Calabria, was vindicated at three councils in Constantinople (1341, 1347, 1351), with the 1351 council enshrining Palamite theology as definitive Orthodox doctrine. His collected works, including the celebrated Triads and the One Hundred and Fifty Chapters, remain foundational to Eastern Orthodox understandings of theosis (deification). He was canonized by the Ecumenical Patriarchate in 1368, nine years after his death, and is commemorated on the Second Sunday of Great Lent.